Screening for osteoporosis

For the middle aged physician it may come as a shock to learn that it is not only little old ladies with curved backs who have osteoporosis. The currently accepted definition of this condition is “a systemic skeletal disorder characterised by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture.”1 This definition introduces the concept of low bone mass and its relation to increased fracture risk but does not require fracture to have occurred. There is some logic to this, in as much as there are no symptoms of osteoporosis before fracture, which occurs late in the disease; most hip fractures, for example, occur in people aged over 80 with associated high morbidity and mortality. It is therefore desirable to identify those individuals at greatest risk because that risk can be roughly halved with effective treatment.2 The introduction of bone density measurements, and in particular dual x ray absorptiometry (DXA), has revolutionised the whole field of osteoporosis, and it is well established that bone mineral density provides the best means of assessing an individual's risk of fracture, with every reduction of 1 standard deviation in bone density equating to a roughly 2-2.5 fold increase in the likelihood of fracture.3 Bone mineral density …